A typical fiber optic connection between a first fiber optic component and a second fiber optic component (e.g., between two fiber optic cables, between a fiber optic cable and a fiber optic module, etc.) is formed by aligning an optical interface of the first fiber optic component (e.g., an end of a fiber optic cable) with an optical interface of the second fiber optic component (e.g., an end of another fiber optic cable or a fiber optic module).
Clean optical interfaces tend to form fiber optic connections with less light distortion and less light energy loss than dirty optical interfaces. Additionally, dirt and dust tend to build up on the optical interfaces of optical components over time. Accordingly, fiber optic component manufactures and fiber optic component users (e.g., technicians) typically take steps to clean the optical interfaces of their fiber optic components. For example, fiber optic cable manufacturers typically specify that the interfaces be cleaned between mates, and typically polish the optical interfaces of fiber optic cable assemblies (a portion of fiber optic cable with a fiber optic connector terminating each end) prior to releasing the fiber optic cable assemblies into the stream of commerce.
Nevertheless, once a fiber optic component is removed from its packaging and handled, it becomes susceptible to dust and dirt. Over time, the accumulation of dust and dirt can become significant, e.g., after unplugging and plugging-in a fiber optic connector of a fiber optic cable assembly multiple times. In extreme situations, the amount of light energy loss can become so great that light detection circuitry at the end of the fiber optic pathway is no longer able to detect the light signal. To avoid such situations, some technicians clean the optical interfaces of fiber optic cable assemblies prior to each use, i.e., prior to connecting the assemblies with other fiber optic components. For example, some technicians wipe the optical interfaces with cleaning material (e.g., cleaning fabric, cleaning paper, or solvents) that tends to remove dirt and dust from the optical interfaces without depositing additional dirt and dust. Other technicians apply a stick-on adhesive to the optical interfaces and then remove the stick-on adhesive in order to remove the dirt and dust.
As another example, in one conventional configuration, a daughter card includes multiple optical interfaces which mate with a circuit board. A technician cleans the optical interfaces of the daughter card at the same time by applying and removing a special cleaning card having sticky cleaning surfaces that correspond to the optical interfaces.
As yet another example, and for conventional configuration having multiple connectors with optical interfaces that connect to optical interfaces of corresponding connectors, a technician cleans the optical interfaces with an aerosol spray. That is, the technician sprays one optical interface in order to clean that interface, then sprays another optical interface in order to clean that other optical interface, and so on.
Unfortunately, there are deficiencies to the above-described conventional approaches to cleaning optical interfaces of fiber optic components. For example, in the conventional approach that involves a technician wiping an optical interface with cleaning material (e.g., fabric or paper), the technician may need to clean several optical interfaces in a short period of time (e.g., to disconnect and reconnect several fiber optic components). To this end, the technician may attempt to reuse the same cleaning material which becomes more contaminated after every use. Eventually, the cleaning material may actually introduce dirt and dust onto the optical interfaces. Such dirt and dust could be visually undetectable but nevertheless degrade performance of the fiber optic component (e.g., distort the fiber optic signal, reduce the effective length of the fiber optic pathway, etc.).
Additionally, in the conventional approach that involves a technician applying an aerosol spray individually to optical interfaces to remove dust and dirt, the spray tends to blow the dust and dirt into the air (e.g., everywhere in an uncontrolled manner). That is, as the technician cleans one optical interface with the aerosol spray, the dust and dirt blown off that optical interface tends to settle on and contaminate other optical interfaces (e.g., exposed and recently cleaned neighboring optical interfaces).
Furthermore, some fiber optic components are disposed in locations which are difficult for a technician to access. For example, fiber optic modules could be mounted to a backplane within a card cage. Such modules could be easily accessible by a circuit board having corresponding fiber optic modules mounted thereon, but difficult to reach by the technician. Accordingly, having a technician manually clean the optical interfaces of such hard-to-reach components, e.g., (i) manually wipe the hard-to-reach optical interfaces with cleaning material or (ii) manually apply and remove a stick-on adhesive, is extremely burdensome.
Also, in the conventional approach that uses a special cleaning card having sticky cleaning surfaces for cleaning multiple optical interfaces of a daughter card that mates with a circuit board, the technician still manually cleans the circuit board that mates with the daughter card (e.g., one optical interface at a time). Accordingly, there is still a high risk of contaminating the optical interfaces of the circuit board, particularly if the technician uses the same cleaning material (e.g., the same cleaning cloth). Furthermore, recently cleaned neighboring optical interfaces which are exposed while other optical interfaces are being cleaned run the risk of collecting dirt and dust since it takes very little time for particles to settle on the optical interfaces.
In contrast to the above-described conventional approaches to cleaning optical interfaces of fiber optic components, the invention is directed to techniques for cleaning an optical interface using a pressurized fluid (e.g., an inert gas or liquid solvent). The fluid can be delivered in an automated manner at a particular time (e.g., during connection of two optical connectors) in order alleviate the burden of a technician having to manually clean each optical interface with conventional cleaning material or a conventional stick-on adhesive each time the technician handles (e.g., disconnects and reconnects) a fiber optic component.
One arrangement is directed to an optical connection system having a first optical connector and a second optical connector. The first optical connector includes a first optical connector housing and a first optical interface fastened to the first optical connector housing. The second optical connector includes a second optical connector housing and a second optical interface fastened to the second optical connector housing. The second optical connector housing defines an aperture that directs fluid (e.g., a gas) over at least one of the first and second optical interfaces. Any contaminating dust and dirt can be blown away thus providing clean optical interfaces for forming fiber optic connections.
In one arrangement, the second optical connector housing further defines a chamber, and the first optical connector housing defines a piston that engages the chamber defined by the second optical connector housing to force fluid within the chamber through the aperture defined by the second optical connector housing. This piston and chamber arrangement provides a simple and convenient mechanism for pressurizing and directing the fluid (e.g., air).
In one arrangement, the second optical connector further includes an elastomer seal (e.g., an O-ring) disposed around an opening of the chamber through which the piston passes when engaging the chamber. The use of the elastomer seal prevents the fluid from leaking out of the chamber through any gaps between the sides of the chamber and the piston by removing such gaps.
In one arrangement, the optical connection system further includes a container (e.g., a replaceable cartridge or canister) that stores compressed fluid. The container includes a trigger that actuates to release the compressed fluid through the aperture defined by the second optical connector housing. The use of the container enables the use of fluids other than air (e.g., complex mixtures). In one arrangement, the compressed fluid is substantially nitrogen which is relatively harmless and inert. In another arrangement, the fluid is a mixture of compressed gas (a propellant) and liquid (e.g., a solvent).
In one arrangement, the first optical connector housing defines a cavity configured to hold at least a portion of the container. Accordingly, a technician can simply remove and replace the container when the container is almost empty such as after a set number of uses (e.g., 20 insertions).
In one arrangement, the optical connection system further comprises a filter that traps impurities. Preferably, the filter is disposed within the aperture defined by the second optical connector housing of the second optical connector. In one arrangement, the filter is a sub-micron filter for filtering out even extremely small particles.
The features of the invention, as described above, may be employed in fiber optic systems, devices and methods and other computer-related components such as those of Teradyne, Incorporated of Boston, Mass.